The goal of this proposal is to determine the effects of diabetes on myocardial energy metabolism and ventricular function. The mechanisms that control rates of neutral lipid synthesis and lipolysis, fatty acid oxidation and ATP production from glycolysis will be determined. In addition, the hypothesis that the alterations in energy metabolism that occur in diabetic hearts may predispose the tissue to damage during mild states of myocardial ischemia will be investigated. These studies will be conducted in hearts removed from both acute and chronic diabetic rates and perfused in the isolated, working heart apparatus.